Rolex GMT Master II

A Rolex GMT-Master II with the red and black bezel, a watch that once belonged to Carlos Menem Jr. and is now held by the Museo del Bicentenario in Buenos Aires. Rolex built the original GMT-Master in the mid-1950s at the request of Pan Am, whose pilots needed to keep track of two time zones at once. The trick is all on the outside. A fourth hand circles the dial once a day and points to a 24-hour bezel, and the two-color insert splits day from night at a glance; on the first models red marked daylight hours and blue the night. The two-tone bezel is what makes a GMT recognizable from across a room.